Use info box at fixed position showing the information for the current mouse position instead an unsteady hover

[joergreichert]

Use fixed info box for attributes (in district map) instead of hover, like done here

• https://baumstatistik.codeforleipzig.de
• https://pumpenkarte.codeforleipzig.de
• https://codeforleipzig.github.io/codingdavinciost2018/